The specific inducer of encystment in Azotobacter vinelandii is Beta-hydroxybutyrate (BHB). 65% of the BHB-carbon incorporated by cysts is found in 5-n-alkyl-1,resorcinols and 6-n-alkyl-4-hydroxy-pyran-2 ones. The mode and control of synthesis of these unique lipids will be studied as well as their possible roles in the differentiation process. The fatty acid synthetase of A. vinelandii will be characterized as well as changes in its properties induced by exposure of cells to BHB. The control of synthesis of the resorcinols is believed to be a function of intracellular reduced nucleotide levels. Kinetic studies of isocitric dehydrogenase, isocitritase and malic synthese will be conducted to determine how competition for the substrate, isocitrate, affects nucleotide levels. The role of reduced pyridine nucleotide transhydrogenase will be assessed.